AIX

AIX

Connect with fellow AIX users and experts to gain knowledge, share insights, and solve problems.


#Power
#Power
 View Only
  • 1.  virtualization nomenclature

    Posted Tue July 14, 2009 11:04 AM

    Originally posted by: SystemAdmin


    Hi,
    with all this cloud buzz, I am getting confused on nomenclature for various levels of virtualization. Does IBM have standard terminology for various

    entities at various levels of virtualization? e.g.:

    1) The physical machine:
    a) the case: "rack"; "server"?, "box"?
    b) the box with a processor (and optionally memory, disk, I/O): "blade"; "server"?, "box"?

    2) An independent entity under control of a single instance of an operating system:
    a) on 1 physical entity: "host"? "server"? "system"?
    b) as part(ition) of a physical entity: "LPAR" (or is that reserved for MainFrames? Or also for pSeries? Then what about VMWare on Intel?); Do we call such a thing also "host"? "server"? "system"?
    c) as virtual machine hosted on an independent entity - think VMWare on Intel: "virtual machine"? "lpar"? "host"? "client"? "server"?

    3) Java Virtual Machine: "virtual machine", "application server"?

    So I think that the terms "server", "host", "system", "lpar", and "virtual machine" are ambiguous and are being used on different levels of virtualization.

    Are there proper definitions to avoid confusion?
    #AIX-Forum


  • 2.  Re: virtualization nomenclature

    Posted Tue July 14, 2009 07:37 PM

    Originally posted by: dukessd


    I'll have a go...

    Lets take a 4 CEC p570 as an example.

    This is one system comprising four boxes that make up the processor complex, this will include the processors, memory and some disks and I/O. It can also have separate disk / I/O boxes attached directly to the system bus.

    So we have one system here, it is called in the world of HMCs and virtualisation a "Managed System".

    That should answer 1)a). It may be in one or more Racks depending on how big it is.

    For 1)b) a box with a processor could be a whole system, or for the larger systems like the p570 the processor complex may be distributed among several boxes. Each of these is a CEC - Central Electronics Complex.

    2) If you mean by "independent entity" a self contained box with one OS instance then any p system can run without virtualisation and just run a single OS. The smaller systems are just like a PC, processor, memory, I/O, disks all in one box. The larger ones are spread around several boxes for flexibility - you only want a couple of CPUs, buy a one CEC system, then you can upgrade by adding processors and then CECs and / or I/O drawers to get to the number you want.

    New one - drawer. Most of the larger systems are rack mount and the boxes are referred to as drawers.

    eg, p570 with 4 CECs and 2 I/O drawers.(bit like a chest of drawers)

    2b) Yes we have LPARs on pSeries, since power4.

    A system can be partitioned into several types of LPAR.
    All physical resources.
    Some or no physical resources. Non physical resources are virtual resources usually provided by another LPAR (or partition - same thing) which runs a modified version of AIX called VIOS - Virtual I/O Server. There is also a version of VIOS called IVM - Integrated Virtual Manager - which as well as providing virtual resources to "client" LPARs can also manage the whole system so there is no need for an HMC.

    Some virtual resources do not need a VIO Server or IVM but come as a function of the system - virtual ethernet for instance is provided by the firmware and hypervisor.

    Virtual serial or tty ports for the console can also be provided by firmware.

    LPARs can runs several operating systems - VIOS, IVM, AIX, LINUX, i.

    Each instance of an OS is a host and a partition. That partition may be a full system partition - uses the whole system, or an LPAR - Logical Partition, which only uses part of a system or "Managed System" where virtualisation comes in to consideration.

    VMWARE, hmm, the closest here, virtual machines on a host OS, etc. would become available in AIX6 and be called Workload Partitions. Each AIX6 instance can host virtual OS instances. And yes you can have these on a full system partition or in an LPAR.

    I think that covered 2c) as well.

    3)yeah, any one of those, a JVM is a JVM, innit!

    Managed system - a whole system that may be made up of one or more boxes and they may be CECs or I/O drawers.
    CEC - a memory and processor complex (usually with a bit of I/O and some disks) that may be a whole system / managed system or a part of a larger system.
    Server - ambiguous, could be a system or an OS instance, not usually used as we have terms that better describe what we are dealing with but usually used in the same was as system or managed system.
    Host - usually an OS instance, be it in an LPAR or on a whole system, or even in a WLP - work load partition.
    System - the whole thing.
    LPAR - logical partition, a subset of the components in a system running its own OS, but may also be hosting virtual devices if a VIOS or IVM OS, or hosting other WLPs if AIX6.
    Virtual machine - all a bit VMWARE for this forum but I guess WLP would be closest.

    Hope this helps and you can pick out the key words to go a googling with.
    #AIX-Forum


  • 3.  Re: virtualization nomenclature

    Posted Wed July 15, 2009 12:52 AM

    Originally posted by: drajarsh


    >>There is also a version of VIOS called IVM - Integrated Virtual Manager - which as well as providing virtual resources to "client" LPARs can also manage the whole system so there is no need for an HMC.<<

    A correction: The IVM isnt a version of VIOS but rather a component of the VIOS software, or to put it differently, the VIOS hosts the IVM.

    As rightly stated, the IVM can manage a whole system however, every system that is to be managed by the IVM needs a separate IVM instance, therefore, IVM is recommended for smaller systems in stand-alone deployments.
    #AIX-Forum


  • 4.  Re: virtualization nomenclature

    Posted Wed July 15, 2009 04:45 AM

    Originally posted by: SystemAdmin


    dukessd, drajarsh: thanx for your clear exposé. I am looking for common terminology across platforms, but OK this is an AIX forum and a complete mapping between different vendor products may be problematic.
    #AIX-Forum